The subject of the present invention is a razor head having an anti-friction element affixed thereto by welding. More particularly, the present invention relates to an improved manner of affixing an anti-friction element to a razor head.
Numerous razors comprising an anti-friction element or strip, also known as a lubricating strip or auxiliary shaving strip, already exist. The anti-friction element may contain a polymer or a blend of polymers, one of the components of which has lubricating or cosmetic properties and is water-soluble. Thus, upon each pass with the razor, a film of cosmetic product or lubricant is applied to the user""s skin, to make shaving easier and/or more comfortable.
Such razors have been described, for example, in patents FR 2 410 541 (corresponding to U.S. Pat. No. 4,170,821 to Booth), EP 0 550 605 (corresponding to U.S. Pat. No. 5,113,585 to Rogers et al.), and EP 0 184 440 (corresponding to U.S. Pat. No. 4,624,051 to Apprille, Jr. et al).
A distinction can be drawn between several groups of lubricating strips which are classified, for example, according to their shape or according to their formulation. Thus, lubricating strips may have a simple structure, that is to say a flat shape, fixed to the razor head, or alternatively may have a complex special-purpose shape which collaborates with the shape of the head in order to provide attachment by nesting or clipping in. There are also a great many formulations for these lubricating strips, which can be produced from a blend of polymer materials or can comprise various superposed layers of polymer(s), this in particular being so as to act as wear indicators, as described, for example, in GILLETTE patent EP 0 772 511 and in WARNER-LAMBERT patent EP 0 773 855 (corresponding to U.S. Pat. No. 6,295,733 to Wexler et al.).
In general, in the case of flat lubricating strips, attachment is by bonding. At the current time, there are three broad families of adhesive available commercially:
adhesives known as xe2x80x9ccyanoxe2x80x9d adhesives, which entail a bonding (and therefore razor manufacturing) process which is slow, because of the lack of tack at the outset, and which also have other disadvantages given that the cyano adhesive penetrates the lubricating strip where it may interact with the constituents, and that it is not very water-resistant;
adhesives of the hot-melt type, which for their part exhibit immediate tack, but make a connection between the lubricating strip and the razor head via a flexible mat, the thickness of which is difficult to reproduce and which may easily be torn off;
thermally activated adhesives which entail a bonding (and therefore razor manufacturing) method which is slow.
Furthermore, the adhesive-bonding attachment methods employ adhesive compositions which come in liquid form of some viscosity. The use of such products is a source of problems in manufacturing methods that operate at a very high rate, such as those used for the industrial-scale manufacture of razors.
It was therefore desirable, in order to alleviate these drawbacks, to find a means of attaching a lubricating strip to the head of a razor which did not lead to modifications to the properties of the lubricating strip, which was easy and quick to use on an industrial scale, and which afforded a very strong connection between the razor head and the lubricating strip.
The use of a lubricating strip consisting of a blend of insoluble polymer and of soluble polymer, which strip was fixed to the shaving head by ultrasonic welding, is described in French application FR 2 769 535 (corresponding to Australian Patent 738251). However, it is desirable to attach a lubricating strip in a manner which is easier to implement and results in reliably high quality.
In accordance with the principles of the inventors, a highly effective lubricating strip and a good speed and ease of attachment of the lubricating strip to the shaving head is obtained through the use of a special fixing means which does not entail the use of an adhesive.
The subject of the present invention is therefore a razor head comprising an anti-friction element arranged near the blades and containing water-soluble agents, the anti-friction element has a layer containing the anti-friction material secured to a sole containing one or more insoluble polymers. The sole is fixed to the razor head by welding.